If EM is using the secondary System Manager and the secondary is unavailable you can use this procedure to switch EM to use the primary System Manager.
Gain access to the Element Manager that is configured to manage the Primary node of the Avaya Aura® MS cluster by using the following emergency login URL: https://<AvayaMS_FQDN>:8443/emlogin.
Navigate to Security System Manager Advanced Settings and ensure the field Use Secondary System Manager server field is unchecked
Click Save.
To apply the change on each node of the cluster, access a Linux shell for each media server in the cluster and restart EM using the command: service avaya.em restart.